Control means for rudders and the flaps thereon



July 27, 1 943. H. Roos ETAL 2,325,548

CONTROL MEANS FOR RUDDERS AND THE FLAPS THEREON Filed Dec. 7, 1940 INVENTORS /28207212' 7 3, 2 BY W2?! ;x. 4';

Patented July 27, 1943 CON TROL DEAN S FOR RUDDERS AND THE FLAPS THEREON Helmut Roos, Johannes Diirr, and WilhelmT. Koch, Dessau, Germany; vested in the Alien Property Custodian Application December '1, i940, Serial No. 368,966 In Germany November 20, 1939 6 Claims.

This invention relates to improvements in control means for rudders and the flaps thereon, and refers to an arrangement whereby a rudder and its flap may be operated through a single actuating rod.

It is an object of the invention to provide a control means for a rudder and its flap including a resilient connection whereby pivotal movement of the flap precedes that of the rudder so that the inclination of the flap, and the air forces acting thereon, may be utilized to assist in moving the rudder. rudder is materially lessened, particularly in the case of larger airplanes flying at high speeds,

though the arrangement is such that perceptible eifort is required to move the actuating rod when flying at slower speeds so that the pilot is not deprived of the sense of touch whereby he ascertains that the mechanism is correctly positioned.

Another object of the invention is to provide such a control means including locking means for the flap to prevent fluttering and normally holding it rigid with the rudder. Because without such locking means, due to the resilient connection, there would be a tendency for the flap to flutter at relatively slow speeds and thereby materially reduce the critical speed of the airplane.

A further object of the invention, in its preferred form, is to provide such a control means including power driven means set in motion by movement of the actuating rod for imparting movement to the flap, because the inclusion of such a locking means adds considerably to the efi'ort required to move the flap so that considerable force must be exerted to move the rod if the entire movement is to be obtained by the exertion of manual effort.

Another object of the invention is to provide such a control means for a rudder and its flap including auxiliary means, preferably operated through a second motor, for adjusting the position of the flap independently of the rudder. Such an arrangement materially increases the 'factor of safety because it prevents pivotal movement of the flap to other positions while the rudder remains stationary, and consequently flne adjustment of the flap may be obtained to produce an exactly balanced condition. It is preferable that such motors be electrical because the wiring and connections therefor are quite light in weight, and again the use of long rods or other parts required in some other forms of installation would result in a springy installation that would permit fluttering of the flap to occur, in addition to which such types of installation would necessitate the inclusion of greater additional weight.

Yet another object of the invention is to provide such a control means including one motor for imparting movement to the flap upon movement of the actuating rod whereby the rudder is Thus the effort required to move the also moved, and a second motor for imparting independent movement to the flap, and to include dual connections and wiring so that either motor may be operatedthrough each switch.

Having thus briefly and broadly stated some of the'objects and advantages of the invention we will now proceed to describe the latter with the aid of the accompanying drawing, in which:

Figure 1 illustrates the invention including manual means for obtaining the entire movement of the rudder and its flap.

Figure 2 shows a modification of the invention wherein movement of the actuating rod causes movement of the flap through power driven means.

Figure 8 is a further modification wherein a second motor is employed for imparting independent pivotal movement to the flap for purposes of trimming, and

Figure 4 is a reduced view of the modification shown in Figure 3 including the dual wiring for the two motors and means for energizing either motor by closing either switch.

Referring first to Figures 1 and 2. I designates a rudder pivoted at Ia, and 2 is a flap pivotally mounted on the rudder at M. 3 denotes a portion of an actuating rod intended to be moved axially. This rod terminates at one extremity in a cylinder 30, having a piston 31) therein which is normally maintained substantially centrally therein by opposed springs 4 and Ba. Extending from the end of the cylinder 3a. remote from the actuating rod 3 and integral with the latter is a rack I which meshes with a pinion 6 mounted for rotation on a piston rod 30 extending from the pistorr'3b.

Referring now to Figure 1, connected to the pinion 6 for rotation therewith is a flexible shaft 8 the opposite extremity of which is connected to a spindle 9 mounted in bearings 9a secured to the rudder I. This spindle 9 is threaded to engage a nut I0 which is held against rotation in a fork I l the other extremity of which is secured to a reach rod 5, and the opposite extremity of the said reach rod is connected to the flap 2 to move it about its axis 2a. The fork II is provided with opposed slots'l I a to receive trunnions Illa extending from the nut ID to permit the rod 5 to change its longitudinal alignment as it moves to impart rotation to the flap 2 about its pivot axis 2a.

The operation is briefly as follows: When the rod 3 is moved axially in either direction the rack 1 causes rotation of the piston 6 and turns the spindle 9 through the flexible shaft 8. Then the reach rod 5 is moved to turn the flap 2. During the initial portion of the movement of the actuacting rod 3 the piston 3b remains stationary due to its arrangement between the opposed springs 4 and to. However after the flap has been turned to a predetermined angle and one of the springs 6 or la has been suillciently compressed the piston 3b and its rod 30 commence to move thereby rotating the rudder I about its axis Ia. Thus movement of the flap 2 occurs first, and when it has been moved to a predetermined angular position the air-forces acting thereon tend to move i it and the rudder I thereby materially reducing the effort that would otherwise be required to move the said rudder. Again due to the fact that movement of the flap 2 and reach rod'.5 is obtained through rotation of the spindle 9 in the nut I0, air forces acting upon the flap cannot change its angular position as the said spindle and nut combination constitute a locking means which precludes any such movement.

In the modification shown in Figure 2 the pinion 6, which is again in mesh withthe rack 'I,-is secured to a rotary contact member I2a which intermittently closes connections between leads I3 and I3a in a switch mechanism I2. I3 terminatein an electric motor I4, and the leads I3a are connected to asource of power 29. Thus when the pinion 6 is turned through movement of the actuating rod 3 the motor I4 is intermittently energized. Connected to the shaft 'of the motor I4 is a worm, I5 which meshes with a segmental gear I6 mounted for rotation upon the rudder I. Connected also to the gear I6 is one extremity of the reach rod 5 the other end of which is again connected to the flap 2 to turn the latter about its axis. Consequently in this embodiment less manual effort is required to turn the flap 2 becauseit is merely necessary to turn the rotary contact member I2a and thereby energize the motor I4 bywhich power is supplied to move the flap through the segmental gear I6 and reach rod 5. In this case again air forces cannot cause movement of the flap upon the rudto operate the motor I4 through leads I3 and in'Figure 4 also through other leads 3| normally connected thereto by a switching means 33. In this'instance the second motor 25 is also provided for trimming the flap 2 and moving it entirely independently of the rudder I.

Extending from the motor I4 is a threaded shaft. I'I having a nut I8 thereon from which a double-armed lever I9 pivoted in the rudder at I9a is actuated. Pivotally connected to the lever I9 by a pin 20a are two arms 20 and 21, which are in turn pivotally connected to other arms 22 and 23 by pins 2 Ia and 23a respectively, while the arms 22 and 23 are also pivoted to one another by a pin 22a. Thus the. arms 20, 2|, 22 and 23 are disposed in the form of a parallelogram and together make a toggle-like connection.

The shaft of the motor 25' has a worm 26 thereon which meshes with a segmental gear 21 pivoted on the rudder I and having an integral lever 21a. Pivotedon the latter is a link 24 the opposite extremity of which is connected to the pin 22a. The adjacent extremity of the reach rod 5 is also pivoted on the pin 23a, and the pin The leads When the motor I4 is intermittently rotated the nut I8 and shifter yoke I9 are moved thereb movingthe toggle-like connection 20, 2!, 22 an 23 and the rod 5 to cause movement of .the flap 2.

5 Then the pin 22a is held stationary by the lever 21a. On the other hand when the motor 25 is energized the worm 26 is turned thereby moving the lever 21a and causing movement of the reach rod 5 through the arms 20, 2I, 22 and 23. During that time the pin 20a i held'stationary by the shifter yoke I9. It will 'be noted that due to the drive imparted from the motors I4 and 25 through the threaded shaft I1 and nut I8, and worm 26 and segmental gear 21 respectively, that the flap 2 is positively held against pivotal movement until and unless either the shaft I! or the worm 26 is turned.

' In Figure 4 leads 32 and 32a connected to a switching means 33 normally connect the motor with a manually operable intermittent rotary switch 28. But so that either motor I4 or 25 can be operated through either switch I2 or 28, the leads 32a from a source of power 30, or the leads I3 from the source of power 29, can, through the 25 means 33 be selectively connected to either set of leads 32 or 3I.

While in the'foregoing the preferred embodiments of the invention have been described and shown, it is understood that the control means is susceptible to such further alterations and modifications as fall within the scope of the appended claims.

What we claim is:

1. A control means of the character described comprising a rudder mounted for movement and having a flap pivoted thereon, an actuating rod yieldingly connected to the rudder for moving the latter, and means cooperable with the rod on initial movement thereof for imparting pivotal movement to the flap prior to movement of the rudder when the rod is moved, said means including coacting elements preventing movement of the flap by air forces exerted thereon.

2. A control means comprising the combination set forth in claim 1, wherein the means for imparting movement to the flap includes a mo-' tor set in motion by movement of the rod.

.3. A control'means comprising the combination set forth in claim 1,,including a second means for moving the flap pivotally while the actuating rod and coacting elements remain stationary.

4. A control means comprising the combination set forth in cliam 1, wherein means for imparting movement to the flap include a motor set in motion by movement of the actuating rod, and a second independently operated motor for moving the flap pivotally while the rod and coacting elements remain stationary.

5. A control means of the character described comprising a rudder mounted for pivotal movement and having a flap pivoted thereon, an actuating rod, a motor, means setting the motor in operation upon initial movement of the rod, and means operated by the motor for moving the flap, said rod being connected to the rudder through a 10st motion connection to impart movement thereto.

6. A control means comprising the combination set forth in claim 5, wherein the means for setting the motor in operation includes means for intermittently operating the motor during continued movement of the actuating rod.

HELMUI' ROOS. JOHANNES DCRR. WILHELM TH. KOCH. 

